How to adjust the heating curve using the Aerona Smart Controller?

Editing the heating curve for a weather-controlled circuit for a Grant air source heat pump system can be completed with ease via the Aerona Smart Controller and its touchscreen display.

What is the heating curve on a heat pump system?

The heating curve functionality with the Aerona Smart Controller is a sophisticated weather compensation which can be enabled if an outdoor weather sensor has been connected. Configuring the heating curve will calculate the weather control adjustments for set-point temperatures. It correlates the circuit water temperature with the temperatures outside so that the flow temperature is automatically adjusted based on the outdoor air temperatures.

The circuit water target temperature is calculated based on the ambient temperature outside the building – the colder it is outside, the higher the water temperature in the circuit will be. With the heating curve correctly configured, the circuit flow temperature will automatically increase when it is colder outside and automatically decreases when the external temperatures are warmer.

The heating curve is configured per circuit and the heating curve selection will provide a line graph representing the required target water temperature against the outdoor air temperature. A recommended starting point is to align the curve to set a 45ºC circuit flow temperature when the external air temperature is -3ºC but the curve can be adjusted should the temperature points not be satisfactory.

How to set the heating curve on a Grant heat pump

The heating curve can be viewed and set as part of the initial set-up for an Aerona Smart Controller using the in-built system configuration tool when configuring the Weather Compensation. As mentioned previously, an outdoor weather sensor must be fitted. 

If you are interested in learning more about the set-up procedures for this smart heat pump controller, please watch our video tutorial here. It is also recommended that heat pump installers refer to the Aerona Smart Heat Pump Controller manual for further set-up assistance and guidance.

How to edit the heating curve on a Grant heat pump

After the initial set-up of the heat pump controller, the heating curve of any circuit can be edited again at anytime. To edit the heating curve on one or more circuits, navigate to the settings via the settings icon (shown below) displayed in the bottom left hand corner of the Aerona Smart Controller’s home screen display.

On the next screen, select ‘Service Settings’, enter the four digit password of ‘0000’ and then press ‘enter’. A menu will then appear – from the options, select ‘Installation Controller’. A list of all of the circuits configured on the system will then display – scroll through this list to find the circuit you want to edit and select the appropriate circuit. On the next screen, scroll through the menu to find and select ‘Heating curve’. You will then see the screen where the heating curve can be edited and adjusted.

On the next screen, select ‘Service Settings’, enter the four digit password of ‘0000’ and then press ‘enter’. A menu will then appear – from the options, select ‘Installation Controller’. A list of all of the circuits configured on the system will then display – scroll through this list to find the circuit you want to edit and select the appropriate circuit. On the next screen, scroll through the menu to find and select ‘Heating curve’. You will then see the screen where the heating curve can be edited and adjusted.

Heating curve edit screen

Once on the heating curve edit screen, the curve can be altered by using the arrows towards the right hand side of the screen to adjust the ‘Curve’ and ‘Shift’ values. If you are editing a heat emitter curve, the ‘Curve’ should remain within the recommended values provided in the heat pump controller manual. For example, the radiator curve should be between 1 and 1.6 and the underfloor heating curve should be between 0.2 and 0.6. 

Meanwhile, the ‘Shift’ value allows you to find the midpoint based on the temperature outside and the desired flow temperature.

Guidelines for adjusting a heating curve

If you or your customer are noticing any of the following, it would be worthwhile checking the heating curve and whether it needs changing:

·        If the outdoor temperature drops and the room temperature increase, this would suggest that the selected heating curve value is too high

·        If the outdoor temperature drops and the room temperature drops as well, this would suggest that the selected heating curve value is too low

·        If during frosty weather the room temperature is comfortable but when it gets warmer, the room is too cold, it would be recommended to increase the heating curve shift and to select a lower heating curve

·        If during frosty weather the room temperature is too cold and when it gets warmer, the room is too hot, it would be recommended to decrease the heating curve shift and to select a higher heating curve

Heat pump controller video tutorial

To watch a tutorial which demonstrates how to adjust the heating curve for a Grant air source heat pump system using the Aerona Smart Controller, please watch the video below.